The invention relates to a combustor of a large rotating furnace, belonging to a component of a smelting furnace. The combustor of the large rotating furnace mainly comprises an air blower (1), an air blower motor (3) and a cylindrical high titanium steel burner nozzle (2) , wherein an air tube (4) is additionally arranged between an air outlet of the air blower (1) and the cylindrical high titanium steel burner nozzle (2) so as to lengthen a distance between the centre of the air blower motor (3) and a fire port (5). By using the combustor of the large rotating furnace, the air blaster motor can be protected against high temperature damage, the service life of the air blaster motor is prolonged, and the production cost is reduced.